Liquid-fuel burner nozzle construction



July 18, 1950 J. cHEc-KON 2,515,494

LIQUIDFUEL BURNER NOZZLE CONSTRUCTION v Filed Dec. 26, 1946 3 Sheets-Sheet l Juventa Hna Gttorneg July 18, 1950 J. cHEcKoN 2,515,494

LIQUID-FUEL BURNER NOZZLE CONSTRUCTIQN Filed Dec. 26, 1946 sheets-sheet 2 j ZhwmtotH /1 yJo/z/z A@hec/fof? July 18, 1950 J. cHEcKoN 2,515,494

y LIQUID-FUEL BURNER Nozzua CONSTRUCTION Filed Dec. 26, 1946 I5 Sheets-Sheet 3 7 jig. j

Srwentor t/0/7/2 Chee/fof? 543% H15 (lttorneg Patented 18, 1950 UNITED STATES PATENT ortica LIQUID-FUEL BURNER NOZZL CONSTRUCTION John checken, om, ma.

Application December 26, 1946, Serial No. 718,281

2 Claims. (Cl. 299-59) The present invention relates to fuel burners, and more particularly to one which is adapted to handle both liquid and gaseous fuels. While not limited thereto, the burner of the present invention is peculiarly well suited for use in an open hearth steel making furnace fired with liquid fuel, such as fuel oil or tar, mixed with a gaseous fuel, such as coke oven gas. The burner also may burn straight liquid fuel or liquid fuel in combination with gaseous fuel in any desired ratio, depending upon the availability of the fuels.

It has long been the practice to heat open hearth furnaces by using a mixture of liquid and gaseous fuels, but many of the prior art burners are yopen to the objection that they become readily carbonized at the tip of the nozzle, with the result that the gaseous fuel is not properly shielded and therefore has a tendency to be deflected upwardly to thereby cause an early destruction of the roof and other parts of the furnace. The burner of the present invention seeks to overcome the above and other inherent defects in the prior art.

One object of the invention is to provide a burner so constructed and arranged that the clogging of the liquid-fuel nozzle is minimized, thus insuring long periods of eilicient operation. For the necessary infrequent cleanings of the burner easy and convenient access is provided.

The invention, then, comprises the features hereinafter described and as particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicati-ve of several of the number of ways in which the principles of the invention may be employed.

In said drawings:

Figure 1 is a sectional view of one end of an open hearth furnace;

Figure '2 is a sectional view taken on the line II-II of Figure 1;

Figure 3 is a plan view of the burner of my invention;

Figure 4 is a sectional view taken on the line IV-IV of Figure 3;

Figure 5 is an end view taken on the line V-V of Figure 3;

Figure 6 is a sectional view taken on the line VI-VI of Figure 4;

Figure 7 is a sectional view taken on the line VII-VII of Figure 4;

Fig. 8 is a sectional view of the front end of the burner;

Figure 9 is a sectional view of the rear end of the burner;

Figure 10 is a sectional view of the nozzle of the fuel burner; and

Figure 11 is a sectional view of a detail of the liquid fuelline that receives the detachable nozzle.

Referring more particularly to the drawings, the numeral I designates one end of a conventional open hearth furnace, the same comprising side walls 2, hearth 3 and roof 4, the hearth I communicating with an air intake 6. Both of vthe end walls I of the open hearth furnace are provided with the usual opening 6 in which there is disposed a burner of a type adapted to handle both liquid and gaseous fuels; for example, fuel oil or tar mixed with coke oven gas.

As is well known to those skilled in the art, in the normal operation of an open hearth furnace, the path of the gases is periodically reversed. Thus the air uptake E at one time serves as an air inlet and at another period of the cycle serves as an outlet for the spent gases which are led through the usual regenerator so as to give up the heat thereto. It is common practice in'open hearth furnace operation, therefore, to periodically reverse the flow of the gas ame through the furnace, thus during one period of operation a fuel burner at the ingoing end of the furnace is active while the burner at the opposite or outgoing end is inactive.

In Figure l the burner indicated as a whole at 8 may be regarded as the active burner at the ingoing end of the furnace. At the opposite or outgoing end of the furnace there will be an identical burner which, however, at that end, will be inactive while the burner as shown in Figure 1 is active. Because of the active and inactive periods of burner operation, there is an inherent problem to be overcome in the normal operation of burners fired with a combination of liquid and gaseous fuel due to the tendency of the inactive burner at the outgoing end of the furnace to become clogged with particles of slag, dirt, or other foreign matter. When such foreign matter aecumulates in the outlet orifices of the burner, it has a tendency to interfere with the proper burner operation.

The novel burner -8 of the invention comprises an outer cylindrical shell-like casing which may conveniently be constructed of a 10-foot length of stock size 12" steel pipe closed at its front end by a closure plate Ill and at its rear end by closure plate I3 (see Figures 3 and 4). The front closure plate In is diagonally disposed in the forward end of the casing and welded in position as shown in Figure 8.

More specifically, a gaseous-fuel pipe I4 is disposed coaxially of the shell 8 and it extends through and projects from a central opening I5 formed in the rear closure plate I3. This gaseous-fuel pipe Il may acceptively be formed of a straight piece of standard stock G-inch pipe about 11 feet long, and at its rearwardly projecting end isprovided .with a gas inlet opening I8 and a clean-out plug I1.

The forward portion of the gaseous-fuel pipe Il is reduced in diameter, as shown at I8, and provided with a attened extremity i9 which seats in a correspondingly shaped aperture 29 in the front closure plate Ill. Preferably the parts are welded together as shown. The reduced and flattened portions i8 and I9 of the gaseous-fuel pipe i4 create a throttling eilect at the gas nozzie and proportionately increases the velocity of the gas flow.

Immediately above the gaseous-fuel pipe Il, but

in spaced parallel relationship with relation thereto, is a protective tube 21, the forward end o! which is telescoped over a short cylindrical sleeve 28, the latter -being seated in an aperture 28 in the front cover plate l0 and welded in position as shown. Also connected to the short cylindrical sleeve 28 and disposed withintube 21 is an atomized liquid-fuel pipe 3i which is of such a smaller diameter as will permit of maintaining an appreciable space relationship between the two pipes.

The rear cover plate i3 is provided with an aperture 33 within which there is disposed and welded a pipe sleeve 35 having a cylindrical portion 36 over which the rearward end of the tube .21 is adapted to telescope. The liquid-fuel pipe 8l extends through the pipe sleeve 35 and projects therefrom as shown.

The rearward, and projecting, end of the liquid-fuel pipe 3l is connected to a suitable atomizer (not shown).

This construction isA conventional except for the novel nozzle construction of my invention, the details of which will now be described.

The nozzle for the fuel burner of the present invention is generally designated at 38 and is shown as comprising a tube which is preferably made of heat-resisting steel with the discharge end of the said nozzle turned down to form a cylindrical portion 39 of smaller diameter which terminates in a tapered shoulder I0. This cylindrical portion 39 of smaller diameter is adapted to telescope within the short cylindrical sleeve 28 as shown. 'Ihe short cylindrical sleeve 28 is provided with a tapered seat 4| against which the tapered shoulder 40 of the nozzle is adapted to seat. The entry end of the nozzle is tapered to a feather edge as shown at 42 on the inside so as to offer the least resistance to ilow of fluids passing therethrough and also to cause the pressure of the incoming uids to hold the nozzle 38 in position.

Water or other coolant is fed into and out of the interior of the casing 8 through inlet and outlet pipes 43 and 44, respectively.

The rapid removal of the nozzle 38 from its seat in the short cylindrical sleeve 28 is accomplished by inserting a slightly hooked rod (not shown) in the entry end of the inner pipe 3|. Should the operator fail to push the loose nozzle far enough back in the inner pipe 3l to reach its seat in the short cylindrical sleeve 28, the steam and liquid fuel pressure will invariably do this.

The air space between the two pipes 21 and 3l is provided to protect the heat contained in the steam and preheated liquid fuel against the effect of the coolant surrounding the tube 21.

During the period when one burner is operating and the other burner is inactive, the discharge end of the inactive burner is exposed to the radiant heat of the furnace and the hot gases passing through the air uptake on their way to the regenerator. This causes the end of the burner to become red hot. The red-hot metal tends to char any oil that might be in pipe 8l. This charred material, which adheres tightly to the inside surface of the pipe end, deilects the name, usually upwardly toward the roof of the furnace.

According to the construction of my invention, the short cylindrical sleeve 28 is exposed to the action of the coolant, the effect being to keep the tip of the nozzle cool in order to prevent the liquid fuel from carbonizing or charring at this point. The discharge end portion 38 of nozzle 38 is thus kept suiilciently cool so that any dripping oil accumulating thereon will not be carbonized into a hard, tightly adherent mass but rather will form a gummy substance which is easily flushed out when the burner is put in the active period or the on-cycle.

While I have shown and described certain specific embodiments of the present invention, it will be readily understood by those skilled in the art that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In a fuel burner having a shell structure forming a coolant chamber, an apertured cover plate on one end of said shell structure, a liquidfuel pipe in said shell structure, and a protective tube surrounding said pipe and extending substantially the full length of said structure, the improvement comprising a short cylindrical sleeve connected to said liquid-fuel pipe and communicating withthe aperture in said cover plate, the forward end of said protective tube being connected to said sleeve, and a detachable fuel nozzle having a discharge end and an inlet end disposed substantially within said liquid-fuel pipe. the body portion of said nozzle disposed within said fuel pipe having an outside diameter greater than the inside diameter of Said cylindrical sleeve, the discharge end portion of said fuel nozzle having a reduced outside diameter, the outside diameter of said discharge end portion being slightly less than the inside diameter of said cylindrical sleeve and forming a shoulder between the discharge end portion and the unreduced body portion of said nozzle, said discharge end portion projecting from said liquid-fuel pipe and fitting slidably within said short cylindrical sleeve with said shoulder in contact with the edge of said cylindrical sleeve.

2. In a fuel burner, the improvement as defined in claim 1 characterizedby the inlet end of said nozzle being tapered to a feather edge.

JOHN' CHECKON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 952,372 Speer Mar. 15, 1910 1,393,562 Matthews Oct. 11, 1921 1,605,035 Junkers Nov. 2, 1926 1,707,772 Robinson Apr. 2, 1929 1,736,675 Steese NOV. 19, 1929 1,844,653 Hechenbleikner Feb. 9, 1932 2,233,916 Creighton Mar. 4, 1941 2,412,579 Hauzvic Dec. 17, 1946 

